What Does No Gestational Sac On My Ultrasound Mean?

Gestational sacs are typically seen on ultrasound by five weeks.

Pregnancy ultrasound
Getty Images/Saso Novoselic

A gestational sac is one of the first signs of pregnancy that can be seen on an ultrasound. When an early pregnancy ultrasound finds no gestational sac, there are a few possible explanations:

It Is Too Early For the Gestational Sac to Be Visible

The gestational sac is typically visible on a transvaginal ultrasound somewhere between three to five weeks of pregnancy, or by the time the hCG level has reached 1500 to 2000.

Before that, even in a viable pregnancy, there is not going to be a visible gestational sac on an ultrasound.

If the pregnancy is definitely past 5 weeks, or the hCG level is higher than 2000, a finding of no gestational sac is more likely to indicate a problem. But when there's no confirmation of hCG levels or any definite evidence of the dating of the pregnancy, the pregnancy might still be in very early stages. In this case, a follow-up ultrasound is warranted. 

The Pregnancy Is Ectopic

Whenever there is no gestational sac visible in the uterus, there is a possibility of ectopic pregnancy. Ectopic pregnancies can be life-threatening or fatal if left untreated. Any time an ultrasound shows no gestational sac, the doctor will most likely want to rule out an ectopic pregnancy, especially if you are showing any symptoms of ectopic pregnancy.

A doctor may be able to diagnose ectopic pregnancy and recommend treatment without a follow-up ultrasound if the hCG levels are high enough that the gestational sac would definitely be visible if the pregnancy was located in the uterus.

It is possible to have an early stage ectopic pregnancy without having clear symptoms of tubal pregnancy. These pregnancies are not always medical emergencies when detected early.

The Pregnancy Is a Miscarriage

If you have experience early pregnancy bleeding or other miscarriage symptoms, a finding of no gestational sac may mean that you've had a very early miscarriage (chemical pregnancy) or that the pregnancy tissue has already left the uterus.

If there are falling hCG levels along with a finding of no gestational sac, the diagnosis is almost certain to be a miscarriage. 

A Word From Verywell

It can be difficult for doctors to determine right away which of the above explanations is behind a pregnancy with no visible gestational sac. Therefore, it is completely natural to feel concerned and anxious, and perhaps even frustrated. You may be told (or see on medical forms) that you have a "pregnancy of unknown location," which simply means that the ultrasound did not show a gestational sac, and the doctors are not sure whether it is an ectopic pregnancy, a miscarriage, or a very early but otherwise normal pregnancy.

Most likely, you will be asked to come back for a follow-up ultrasound and monitoring of your hCG levels. Together, these repeat tests should give you a clear answer. The wait can be difficult but may be necessary for your doctor to be certain of your diagnosis.


American Pregnancy Association. (August 2015). Concerns Regarding Early Fetal Development.

Deutchman M, Tubay AT, Turok DK First Trimester Bleeding. Am Fam Physician. 2009 Jun 1;79(11):985-92. 

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